Fluid-operated percussive tool.



L. C. BAYLES. FLUID OPERATED PERCUSSIVE TOOL.

APPLICATION FILED mac. 31. 1914.

Patented Mar. 12, 1.918.

WITNESSES.

I 7% 5 IQ 7" 3 2 5 15 12 l/Vl/E/VTOI? LEWIS C. BAYLES, F EASTON, PENNSYIi-VANIA, ASSIGNOR TO INGERSOLL-RAND COM- PANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

FLUID-OPERATED PERCUSSIVE TOOL.

Specification of Letters Patent.

Patented Mar. 12, 1918.

Application filed December 31, 1914. Serial No. 879,881.

ing is a specification. I

his invention relates to fluid operated percussive tools, and more particularly to tools of the type wherein the admlssion of fluid to opposite ends of thecylinder. is controlled solely by the movement of the piston, without the use of intermediate valve mechanism.

The object of this invention is to provide a tool af this type in which the full pressure areas of the piston are alternately exposed to live fluid pressure, and the excessive weight of piston and leakage eliminated, which have heretofore been unavoidable in tools of this type, such as shown, for instance, in the patent to Keller, No. 549,514, dated November 12th, 1895.

This object is accomplished by the invention, practical embodiments of which are shown in the accompanying drawings, in which-- Figure 1 shows a diagrammatic longitudinal section of a tool embodying my invention while p 2 shows a similar section of a modifiin which the inlet arrangement is the same, the exhaust mechanism being some modified. I

The tool, as shown in Fig. 1, comprises a cylinder 1, with a bore of two diameters, a larger forward bore 2, and a smaller rearward bore 8. In the cylinder slides a piston having a. head 4 fittin the larger forward bore 2, and a shank 5 tting the smaller rearward bore 3, the shank 5 having two depressions or necks, a forward neck 6, close to the piston, and a rearward neck 7 near the rearward end of the shank. Fluid is admitted to the cylinder throu h an inlet passage 8' which opens into the si e of the small bore "3 near its forward end. The neck 6 is so the piston is in the position shown in Fig. 1 there is live pressure both on the rear face of the piston head land on the rear face of the shank 5, and thus is exerted on the full effective rear pressure surface of the piston. To admit fluid to the forward end of the bore 2 a port 10 is provided in the side of the bore 3 somewhat rearward of the passage 8, and a passage 11 leads from the port 10 from the forward end of the bore 2. This port 10 is put into communication with the rearward passage 8 at the proper time by means of the neck 7 which is so placed and of such a length that when the pistonis at or near the end of its forward stroke, as shown in Fig. 2, fluid passes from the passage 8 past the neck 7 and through port 10 and passage 11 to the forward end of bore 2. The. exhaust of'fluid from the opposite sides of the piston is shown in Fig. 1 to be accomplished by a port 12 which leads to atmosphere from the central portion of the bore 2 and is uncovered by the piston at each end of the piston stroke, allowing escape of fluid alternately from the two sides of the piston.

place through ports 13 and 14 in the'ends of the bore 2 and is controlled by a valve 15 this exhaust arrangement forming no part of the present invention, but being fully described in the co-pending application of F. M. Slater, Serial No. 879,860 filed December 31, 1914.

The operation of the tool will be obvious from the above description. When the piston is in the position shown in Fig. 1 fluid will be admitted through passage 8 and past the neck 6 to the rear end of bore 2 and also to the rear end of bore 3 through the passage 9, thus exerting a forward pressure on the rear face of the piston head 4 andthe rear face of the shank 5. At the same time, the forward end of the bore 3 will be open to exhaust, {either through the port 12 as shown in Fig. 1, or the ports 12 and. 14 in the form shown in Fig. 2. The piston will then moveforwardly, the admission of fluid to the rear surfacesof the piston being cut off when the rear end of neck 6 passes be yond the forward edge of the passage 8. After this point is reached the piston will move forward through theexpansion of the admitted fluid until the rear face of'the piston head passes the port 12, when the fluid of the rear ends'of bores 2 and 3 will be ex- In the form shown in Fig. 2, exhaust takes hausted to atmosphere. At the same time th1s exhaust is taking place, the neck 7 will open communication between the passage 8' above described cycle oi operations will be repeated.

It will be seen that by controlling the admission to the ends of the cylinder by the shank 5 which can be of comparatively small diameter, and admitting fluid also to the end of the smaller bore to exert pressure on the end of the shank 5,'the lull. rear pressure surface of the iston is utilized, and at the same time the weight of the iston and the opportunitv for leakage is greatly lessened, as comare with tools of the type shown inth'e seller patent, mentioned above.

It is to be understood that while the present showing and other forms and modifications are included within the spirit and scope oi". the same, as expressed in the claims I What 1 claim is: 1. In a fluid operated percussive tool, a cylinder having a bore of two diameters and a piston having a head fitting the larger portion of said bore and a shank fitting the smaller portion of said bore, and means for intermittently admitting fluid, to accom: plish the stroke of the piston in the for ward direction by exerting pressure on the end surface of said shank and the corresponding surface of said head and for intermittently exerting fluid pressure only on the surface of said head opposed to the two first mentioned stroke of the piston in the other direction.

2. In a fluid operated percussive tool, a cylinder, having a bore of two diameters, a piston having a head fitting the larger portion of said bore and a shank fitting the smaller portion of said bore, and passages controlled by said shank for directly admitting fluid pressure alternately to the face of said shank and the corresponding face of said head and to the opposite face of said head.

3. In a fluid operated percussive tool, a cylinder having a larger forward bore and a smaller rearward bore, a piston having a head fitting in said larger bore and a shank fitting in said smaller bore, and passages controlled by said shank for directly admitting pressure to the rear "faces of said piston head and said shank near the rear end of the piston stroke, and to the forward face of said head near the forward end oi said piston stroke.

4. In a fluid operated percussive tool, a cylinder having a larger forward bore'and a smaller rearward bore, a head fitting said forward here and a shank fitting said reardescription discloses certam specified modifications oi? the invention,

surfaces toaccomplish the .ontire rear suryface messes ward bore, nuid inlet passage opening into the side of said smaller bore, and passages controlled by said shank lor admitting fluid from said inlet passage at the same time to the rear ends of said bores near the rear end of the piston stroke, and for admitting fluid to the forward end of said larger bore near the forward end of the piston stroke.

5. In a fluid operated percussive tool, a cylinder having a larger forward bore an a smaller rearward bore, a piston having a head fitting said fitting said smaller bore, said shank a plurality of depressions, a fluid conduit leading into the Side of said smaller bore and ports and passages controlled by said depressions whereby said cylinder to exert pressure alternately on the entire rear surface of said piston,

and on the forward surface of said piston head.

6. In a fluid operated percussive tool, a cylinder having a larger forward bore and a smaller rearward bore, a piston having a heady fitting said larger bore and a shank fitting said smallerbore, and ports and passages controlled is directly admitted to said cylinder to exert pressure alternately on the entire rear sur'- face of said piston and on the forward surface of said piston head.

7. In a fluid operated percussive tool, a.

cylinder having a larger forward bore and a smaller rearward bore, a piston having a head fitting said forward bore and a shank fitting; said rearward bore, a passage connecting the rear ends of said bores, a fluid nlet passage controlled by said shank for intermittently conveying fluid to the rear ends of said cores, and means for intermittently conveying fluid to the forward end of said larger bore.

8. ln a fluid operated percussive tool, a, cylinder having a larger forward bore and a smaller rearward bore, a piston having a head fitting said larger bore, and a shank fitting said smaller bore, a fluid inlet pasfluid is admitted to by said shank whereby fluid I sage controlled by said shank for conveying fluid to exert pressure intermittently on the of said piston and means for conveying; fluid intermittently to exert pressure on the forward surface of said piston. V i

9. A percussive fluid motor comprising in combination a cylinder of two diameters, a iston therefor having an enlarged head and a relatively small head, said enlarged head presenting an intermediate pressure receiving area and an oppositely efl ective pressure receiving area and said small head presenting a third pressure receiving area, and valveless pressure fluid conduit means controlled by said piston providing a substantial period of pressure fluid expansion on each of said pressure receiving areas.

wil

messes receivmg area and an oppositely effective pressure receiving area an said small head presenting a third pressure receiving area, and valveless pressure fluid conduit means controlled by said piston providing a substantial'period of pressure fluid expansion on said intermediate and third pressure re ceiving-areas.

11. A percussive fluid motor comprising in combination, a cylinder of two diameters, a piston therefor having anenlarged head and a relatively small head, said enlarged head presenting an intermediate pressure receiving area and an o positely eflective pressure receiving area, said small head presenting a third pressure receiving area ei-' fective to move said piston in the same direction as said intermediate pressure receiving area, piston controlled pressure fluid admissionmeans initially to adm t pressure fluid both to said intermediate pressure receivin area and to said third pressure receivin area, and a piston controlled port for con ucting pressure fluid from said admission means to said oppositely efl'ective pressure area.

12. A percussive fluid motor comprising, in combination a cylinder of two diameters, a piston movable therein having heads of different diameter, said cylinder and iston providing three pressure chambers arge, small and intermediate" and piston controlled pressure fiuid distributing conduit means providing initial admission of pressure fluid to said intermediate pressure chamber, and the admission of pressure fluid from said intermediate chamber to said small pressure chamber.

13. A percussive fluid motor'compnsing, in combination, a cylinder of twojdiameters; a piston movable therein having heads of different diameter, said cylinder and piston providing three pressure chambers large, small and intermediate; and piston controlled valveless pressure fluid distributing conduit means providing initial admission of live pressure fluid to a plurality of said chambers followed by a period of pressure fluid expansion in such chambers.

14. In a fluid operated percussive tool, a cylinder having a bore of two diameters,-a piston having a head fitting the larger portion of said bore and a shank fitting the smaller portion of said bore, and passages controlled by said shank for admitting fluid pressure past said. shank alternately to the iaceiof said head to the opposite iace of said 15. In a fluid operated percussive tool, a cylinder having a bore of two diameters, a piston having a head fittin the larger portion of said bore and a s1 ank fitting the smaller portion of said bore, and-passages controlled by said shank for admitting fluid pressure through said passages alternately to the face of said shank and the correspending face of said head to the opposite face of said head. I

16. In a fluid operated percussive tool, a cylinder having a bore of two diameters,a piston having a head fitting the larger portion of said bore and a shank fitting the face of-. ..said shank and the corresponding smaller portion of said bore, and passages controlled by said shank for admitting pressure past sald-shank to the rear face of said piston head and said shank .near the rear --end of the piston stroke and to the forward face of said head near the forward end of In testimony whereof, I have hereunto set my hand. LEWiS-(h BABYLES. Witnesses: I

Howann S'Bnenvnnn,

finsnnnon Mann. 

